Over the years a great deal of interest has focused on the art of etching patterns into surfaces of objects. Such patterns can be decorative, informative, can be for the purpose of providing nonskid surface properties, can be for forming copper printed wiring board patterns, and can be useful in many other applications where a specific pattern is desired. Typically, in forming such patterns by etching, a liquid photoresist composition is applied in a thin film to an object's surface. The photoresist composition is commonly a nonaqueous solution or suspension of photo-sensitive compounds in a solvent. The liquid photoresist film is dried and can then be exposed to light in a desired image. The pattern is developed conventionally and the revealed surface is contacted with an etchant. Once the pattern has been fully formed by the action of the etchant in the revealed surface, the exposed resist can be removed with standard methods. As can be seen by the above description, such processes can be labor intensive and can be lengthy.
Further, certain photoresist compositions have serious drawbacks with respect to forming patterns in surfaces that are sensitive to water. Such surfaces can be water soluble or can be substantially hydrophilic and can swell or otherwise be partly dissolved or harmed by the presence of substantial quantities of water. Since some photoresist compositions can be water based and can be developed with a water spray, such resists cannot be used in conjunction with aqueous sensitive surfaces.
Still further, the use of many photoresist compositions on curved or contoured surfaces can pose serious problems. First, the transfer of a planar figure onto a curved surface by optical means can result in the substantial distortion of the shape or appearance of the figure. Such distortion can result in a ruined workpiece. Second, forming a uniform thickness of a liquid photoresist can be virtually impossible on such a surface. In the absence of uniform resist layers the pattern developed in the resist can often be incomplete, changed in shape or size, or can be otherwise distorted.
Accordingly, a substantial need exists for a photoresist that is easy to use, can readily develop an image or pattern and can be used on both water sensitive surfaces and surfaces having curves or contours.